Methods for The Testing of Nanopowder

Methods for the testing of nanopowders produced by wires electric explosion were considered. The following characteristics were proposed for the testing of nanopowders : main substance content, characteristic sizes of particles, specific surface area etc..Comment: Submitted on behalf of TIMA Editions (http://irevues.inist.fr/tima-editions

Strong decays of N∗(1535)N^{*}(1535) in an extended chiral quark model

The strong decays of the $N^{*}(1535)$ resonance are investigated in an extended chiral quark model by including the low-lying $qqqq\bar{q}$ components in addition to the $qqq$ component. The results show that these five-quark components in $N^{*}(1535)$ contribute significantly to the $N^{*}(1535)\to N\pi$ and $N^{*}(1535)\to N\eta$ decays. The contributions to the $N\eta$ decay come from both the lowest energy and the next-to-lowest energy five-quarks components, while the contributions to the $N\pi$ decay come from only the latter one. Taking these contributions into account, the description for the strong decays of $N^{*}(1535)$ is improved, especially, for the puzzling large ratio of the decays to $N\eta$ and $N\pi$.Comment: 6 pages, 1 figur

Hunting and trapping strategies in the coastal mountains of northern Lebanon during the Epipalaeolithic

Relative to other regions of the Levant, our knowledge of the adaptations of Epipalaeolithic hunter-gatherers to the late Pleistocene environments of the coastal mountains of the central and northern Levant are extremely limited. However, recently excavations at two adjacent caves at Moghr el-Ahwal in the Qadisha Valley of northern Lebanon have provided a rich record, particularly of hunting and trapping strategies from the period following the Last Glacial Maximum (LGM) until the Bølling/Allerød interstadial. The dominant prey species, which varied in proportions through time, included: wild goat; roe, red and fallow deer; as well as fox, hare, squirrel and partridge. These document the exploitation of a wide spectrum of habitats, and demonstrate the expansion of forest cover through this period. Comparisons are made with food procurement strategies through the Epipalaeolithic in the wider region

Binary pulsars as probes of a Galactic dark matter disk

As a binary pulsar moves through a wind of dark matter particles, the resulting dynamical friction modifies the binary's orbit. We study this effect for the double disk dark matter (DDDM) scenario, where a fraction of the dark matter is dissipative and settles into a thin disk. For binaries within the dark disk, this effect is enhanced due to the higher dark matter density and lower velocity dispersion of the dark disk, and due to its co-rotation with the baryonic disk.We estimate the effect and compare it with observations for two different limits in the Knudsen number ($Kn$). First, in the case where DDDM is effectively collisionless within the characteristic scale of the binary ($Kn\gg1$) and ignoring the possible interaction between the pair of dark matter wakes. Second, in the fully collisional case ($Kn\ll1$), where a fluid description can be adopted and the interaction of the pair of wakes is taken into account. We find that the change in the orbital period is of the same order of magnitude in both limits. A comparison with observations reveals good prospects to probe currently allowed DDDM models with timing data from binary pulsars in the near future. We finally comment on the possibility of extending the analysis to the intermediate (rarefied gas) case with $Kn\sim1$.Comment: 15 pages, 6 figures. Few comments and references added, version accepted for publication in Physics of the Dark Universe (PDU

Acoustically evoked potentials in two cephalopods inferred using the auditory brainstem response (ABR) approach

It is still a matter of debate whether cephalopods can detect sound frequencies above 400 Hz. So far there is no proof for the detection of underwater sound above 400 Hz via a physiological approach. The controversy of whether cephalopods have a sound detection ability above 400 Hz was tested using the auditory brainstem response (ABR) approach, which has been successfully applied in fish, crustaceans, amphibians, reptiles and birds. Using ABR we found that auditory evoked potentials can be obtained in the frequency range 400 to 1500 Hz (Sepiotheutis lessoniana) and 400 to 1000 Hz (Octopus vulgaris), respectively. The thresholds of S. lessoniana were generally lower than those of O. vulgaris

Resolving the pulsations of subdwarf B stars: HS 0039+4302, HS 0444+0458, and an examination of the group properties of resolved pulsators

We continue our program of single-site observations of pulsating subdwarf B (sdB) stars and present the results of extensive time series photometry of HS 0039+4302 and HS 0444+0458. Both were observed at MDM Observatory during the fall of 2005. We extend the number of known frequencies for HS 0039+4302 from 4 to 14 and discover one additional frequency for HS 0444+0458, bringing the total to three. We perform standard tests to search for multiplet structure, measure amplitude variations, and examine the frequency density to constrain the mode degree $\ell$. Including the two stars in this paper, 23 pulsating sdB stars have received follow-up observations designed to decipher their pulsation spectra. It is worth an examination of what has been detected. We compare and contrast the frequency content in terms of richness and range and the amplitudes with regards to variability and diversity. We use this information to examine observational correlations with the proposed $\kappa$ pulsation mechanism as well as alternative theories.Comment: 32 pages, 18 figures, 7 tables. Accepted for publication in MNRA

Entropy and Its Quantum Thermodynamical Implication for Anomalous Spectral Systems

The state function entropy and its quantum thermodynamical implication for two typical dissipative systems with anomalous spectral densities are studied by investigating on their low-temperature quantum behavior. In all cases it is found that the entropy decays quickly and vanishes as the temperature approaches zero. This reveals a good conformity with the third law of thermodynamics and provides another evidence for the validity of fundamental thermodynamical laws in the quantum dissipative region.Comment: 10 pages, 3 figure

Epipalaeolithic and Pre-Pottery Neolithic burials from the north Lebanese highlands in their regional context

Archaeological human remains and their funerary contexts provide valuable insights into social and ideological lives as well as the origins, health and activities of past communities. In the southern Levant extensive cemeteries from the Late Epipalaeolithic (Natufian) and Pre-Pottery Neolithic (PPN) have been recognized, although burials from earlier periods are sparse. Elsewhere in the Levant the record from the whole Epipalaeolithic is poor. Excavations at two adjacent caves at Moghr el-Ahwal in the Qadisha Valley of northern Lebanon have provided a window into human lives and mortuary practices from an otherwise poorly known region. This includes material from contexts with radiocarbon dates ranging from the late Kebaran, Geometric Kebaran and Natufian (c. 19–13.8 ka cal BP), as well as directly dated skeletal material from the mid to late Pre-Pottery Neolithic B (c. 9.9–9.5 ka cal BP). Although this forested mountain area may have been isolated from other regions in the Levant, the burial practices show links to the wider area